A 1.8-2GHz VCO with automatic compensation for bond wire inductance variation

A fully integrated voltage-controlled oscillator (VCO) with automatic compensation for bond wire inductance variation is presented. In the proposed design, a novel inductance compensation control circuit combined with a switched-capacitor array is employed. The switched-capacitor array together with a varactor is used to form the capacitive portion of the LC tank of the VCO. The inductance compensation control circuit compares the VCO output frequency with the reference frequency, then it will adjusts the control signals of the switched-capacitor array to compensate the inductance variation caused by bond wire length variation. The simulation results show that the VCO can be tuned between 1.8-2.0 GHz despite of the inductance variation of up to -40% from the desired inductance. The phase noise is as low as -124 dBc/Hz at 600 KHz offset frequency with 1.8-V supply voltage and 2.0-mA current consumption. The good performance (i.e. low phase noise and low power consumption) achieved by the VCO attributes to the high-Q bond wire inductor.